Backpack



FIG. 1 is an elevated front perspective view of a backpack;

FIG. 2 is a front view of the backpack depicted in FIG. 1;

FIG. 3 is a back view of the backpack depicted in FIG. 1;

FIG. 4 is a right view of the backpack depicted in FIG. 1;

FIG. 5 is a left view of the backpack depicted in FIG. 1;

FIG. 6 is a top view of the backpack depicted in FIG. 1; and,

FIG. 7 is a bottom view of the backpack depicted in FIG. 1. 

CLAIM The ornamental design for a backpack, as shown and described. 